A really good idea is to start shopping at markets. Buy your fruit and vegies in season, they'll be cheaper.
Go to a place that sells beans + lentils + all that yummy stuff by the kilo from huge bags, and you just scoop out how much you want. Soooo much cheaper and you help save the enviroment from all that plastic by excluding pre-packaged foods.
I get my TVP dry from the markets for $3.50 (australian) a kilo (and TVP is ultra light dry!) 1kg would be a reeeeally really massive! And I soak it myself at home.

You `can get real cheap tofu blocks at the market, too!